DPPH
solution was freshly prepared by dissolving 24 mg DPPH in 100 ml
methanol, stored at -20°C before use. 10 μl of the sample was
added to 140 μl distilled water and allowed to react with 2850 μl of
DPPH reagent (190 μl reagent + 2660 μl distilled water) for 24 h in
the dark condition. Absorbance was measured at 515 nm.